/* PeerConnectionIn - Handles incomming messages and hands them to PeerState.
   Copyright (C) 2003 Mark J. Wielaard

   This file is part of Snark.
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

package org.klomp.snark;

import java.io.*;
import java.net.*;
import java.util.*;

class PeerConnectionIn implements Runnable
{
  private final Peer peer;
  private final DataInputStream din;

  private Thread thread;
  private boolean quit;

  public PeerConnectionIn(Peer peer, DataInputStream din)
  {
    this.peer = peer;
    this.din = din;
    quit = false;
  }

  void disconnect()
  {
    if (quit == true)
      return;

    quit = true;
    Thread t = thread;
    if (t != null)
      t.interrupt();
  }

  public void run()
  {
    thread = Thread.currentThread();
    try
      {
	PeerState ps = peer.state;
	while (!quit && ps != null)
	  {
	    // Common variables used for some messages.
	    int piece;
	    int begin;
	    int len;
	
	    // Wait till we hear something...
	    // The length of a complete message in bytes.
	    int i = din.readInt();
	    if (i < 0)
	      throw new IOException("Unexpected length prefix: " + i);

	    if (i == 0)
	      {
		ps.keepAliveMessage();
		continue;
	      }
	    
	    byte b = din.readByte();
	    Message m = new Message();
	    m.type = b;
	    switch (b)
	      {
	      case 0:
		ps.chokeMessage(true);
		break;
	      case 1:
		ps.chokeMessage(false);
		break;
	      case 2:
		ps.interestedMessage(true);
		break;
	      case 3:
		ps.interestedMessage(false);
		break;
	      case 4:
		piece = din.readInt();
		ps.haveMessage(piece);
		break;
	      case 5:
		byte[] bitmap = new byte[i-1];
		din.readFully(bitmap);
		ps.bitfieldMessage(bitmap);
		break;
	      case 6:
		piece = din.readInt();
		begin = din.readInt();
		len = din.readInt();
		ps.requestMessage(piece, begin, len);
		break;
	      case 7:
		piece = din.readInt();
		begin = din.readInt();
		len = i-9;
		Request req = ps.getOutstandingRequest(piece, begin, len);
		byte[] piece_bytes;
		if (req != null)
		  {
		    piece_bytes = req.bs;
		    din.readFully(piece_bytes, begin, len);
		    ps.pieceMessage(req);
		  }
		else
		  {
		    // XXX - Consume but throw away afterwards.
		    piece_bytes = new byte[len];
		    din.readFully(piece_bytes);
		  }
		break;
	      case 8:
		piece = din.readInt();
		begin = din.readInt();
		len = din.readInt();
		ps.cancelMessage(piece, begin, len);
		break;
	      default:
		byte[] bs = new byte[i-1];
		din.readFully(bs);
		ps.unknownMessage(b, bs);
	      }
	  }
      }
    catch (IOException ioe)
      {
	// Ignore, probably the other side closed connection.
      }
    catch (Throwable t)
      {
	Snark.debug(peer + ": " + t, Snark.ERROR);
	t.printStackTrace();
      }
    finally
      {
	peer.disconnect();
      }
  }
}
